Nissan 300zx failing smog check. Entered in smog machine as dual exhaust

Hello. My 1993 Nissan 300zx is not passing the smog check! I spoke with the smog technician and I mentioned that the car passed the smog test 2 years ago with no problems. This is what I found the on the smog reports for 2009 and 2012: in 2009 the technician reported my exhaust as a DUAL exhaust system. Now in 2012 this new tech is reporting my exhaust as a SINGLE. Is this why the car is not passing the smog check? The car has not been modified. Per the previous owner everything on the car is original. Is this new tech entering the wrong information?

Answer:		The current technician is correct. Unless your Nissan 300zx is a Turbo model, it has a single exhaust system. Although it may appear the system is a dual (because of two tailpipes) it is actually a single exhaust system because of an H-pipe connecting the 2 exhaust banks prior to the Catalytic Converter. We can not be certain having entered into the smog machine incorrect data relative to your vehicle's exhaust would have produced different pass or fail results. The smog check regulations require that dual exhaust vehicles have smog test emission probes inserted into each exhaust pipe during the smog test. This would allow for sampling of exhaust from both banks of the engine. At this point it appears your Nissan 300zx is being smog tested properly. Mike - SmogTips Support posted by SmogTips Support